Stenciling machine



Nov. 2 '1926.

L.A.THATCHER STENCILING MACHINE Filed March 9, 1925 I Afforny Patented Nov. 2, 1926.

UNITED STATES PATENT OFFICE.

.LINDEN A. THA'ICHER, OF BELLEVILLE, NEW JERSEY, ASSIGNOR TO UNDERWOOD TYPEWRITER COMPANY, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE.

STENCILING- MACHINE.

Application filed March 9, 1925. Serial No. 14,091.

This invention relates to duplicating machines in which a perforated drum is covered with a blanket saturated with ink applied to the inner wall of the drum and in which the blanket is overlaid with a stencil blank between which and a pressure roll the sheets to be stenc-iled are passed.

In this kind of a machine it is sometimes desirable tohave an ink-fountain fast to the frame o-fthe machine from which a small amount of ink is measured and squeezed out of the fountain upon the inner wall of the drum which ink is then spread by means of a brush.

One of the features ofthis invention relates to means whereby the ink-fountain may be attached to anyof the late model Underwood duplicators with little or no alteration thereof. To this end the ink-fountain is mounted at the end of an ink-duct or hollow shaft which may substitute the regular rear shaft upon which the drum is revolubly mounted.

Another feature of this invention is to simplify and improve the construction of hand manipulable brushes for spreading the ink on the drum. To this end, means are provided whereby the brush may easily be detached from its operating handle for the purposes of cleaning, replacement or repair. Improved means are also provided whereby the brush may be supported when not in use upon the inwardly projecting end of the hollow shaft held withinthe drum and bodily removed from its support for use.

Another featurerelates to means for controlling the movement of the brush within the drum when spreading the ink. In order to prevent the ink from being spread too near the ends of the drum and thus confine the ink where needed, the brush is provided with side plates overextending the brush for preventing the bristles of the brush from reaching the ends of the drum.

Other features and advantages will herein after appear.

In the accompanying drawings,

Figure 1 is a cross-sectional view in elevatic-n showing a portion of the drum, the supporting bracket, the ink-fountain mounted on a supporting hollow shaft and the brush on the shaft.

I Figure 2 is a plan view showing a portion of the drum and the ink-fountain.

hand.

Figure 3 is a disassembled perspective view of the brush and its operating handle.

In the normal operation of the machine, the sheet to be stenciled is passed between a perforated drum 10 and a pressure roll cooperating therewith. The drum is covered with an ink pad or blanket 11 to feed ink to the sheet to be stenciled through the impressions on the stencil sheet interposing the blanket and the work sheet.

hen the blanket l1 dries up it is necessary to re-ink it, and to this end there is provided a. brush 12 normally hung inside the drum. The brush is separated from its support by gripping a handle 13 with one Then a plunger 14: is depressed against a restoring spring 15 and a predetermined amount of ink in an ink-fountain 16 is ejected through a duct 17 which is closed to prevent dripping of the ink while not being used by means of a check-valve 18 which is held against its seat by a backing spring 19 which is in turn backed by a screw 20 at the end of the duct 17. The brush having been removed from its supporting stud which inthis case is a shaft 21 into which the ductl'? is bored, a downwardly directed hole 22 in the shaft 21 serves as a passage for the ink when squeezed out of a measuring cylinder 23 by the pressure of a piston 2 which fits thereinto. The piston is fast to a plunger-shaft 25' by means of a cross pin 26 and the outward movement of the piston is limited-by a pin 27 driven into the plunger-shaft.

The ink-fountain, as shown in the drawings, consists of a round receptacle 28 into which the cylinder 23 is bored, and a cover 29 fast to the receptacle by means of screws 30. The upper end of the cylinder opens into the receptacle and is provided with a slot 24L at the side thereof, thereby providing a passage for the ink when the piston is in its uppermost position. The cover is provided with a cap 31 for re-iilling the fountain and the cap is screwed into the cover which is also provided with a housing 32 for the spring 15, said housing beingbored into a downwardly extending portion 33 forming an integral part of the cover.

To facilitate the adaptation of this type of ink-fountain to existing machines of the Underwood type with little or no alteration thereof, the shaft 21 is screwed into the re:

ceptacle at 34 preferably with pipe thread to insure an oil-proof joint between the two members. As it is diflicult to predetermine the position of the hole 22 relatively to the ink-fountain, so that the fountain will stand in an upright position while vertically placing the hole in the lower wall of the hollow shaft, it is proposed to drill the. hole after assembling together the shaft and the r ceptacle, thus rendering the position of the hole relatively to the fountain an easy matter, The shaft 21 may thus be inserted in the existing machines which are provided with a plain stud upon which the drum is revolubly mounted, by withdrawing the stud and placing the shaft in its place. Said shaft 2]. is fast to a supporting bracket 35 and extends into the drum forming a journal for the spider 36 and a hanger for the brush. Said stud is usually fastened by a set-screw 36, and the same screw may be used for fastening shaft 21.

The drum is removable in the usual manner by releasing the locking piece 37 from engagement with a groove 38 in the spider 36, and said locking piece is rockably mounted on a pin 39 fast to the bracket 35, the locking piece being held in engagement with the groove by means of a spring 40.

It is desirable to keep the brush out of the way when not being used, and to this end there is provided a hole 41 in the body 42 of the handle 13, which hole is slightly larger than the overextending portion 43 of the shaft 21 upon which the brush is hung when not in use as shown in Figure 1.

One of the features of this brush is that the same may be separated from its operating handle as shown in Figure 3 for the purpose of cleaning or replacing the brush. Said Figure 3 shows also the means for attaching the two members together which include two grooves 44 in the body of the handle and two longitudinally extending ribs 45 which fit into the grooves 44 when the two members are assembled together.

To prevent the accidental displacement of the brush from its handle, there is provided a set-screw 46 which fits into a tapped hole in the body of the handle and binds the ribs 45 against the sides of the grooves.

For the purpose of controlling the movement of the brush within the drum and to prevent the bristles 47 from spreading the ink too near the edges of the drum, the brush is provided with side plates 48 fast thereto by means of fasteners 49. Said side plates overextend the brush at both ends so that the ends 50 of the plates 48 strike a rim 51 in the spider 36 and prevent the movement of the brush beyond the inking surface on the drum. At the front end, the ,drum is provided with a supporting ring '69 which is also provided with a rim 53 to limit the forward movement of the brush.

incense The plates 48 are provided with inwardly extending bends 54 to afford a wearing surface at the ends thereof and to prevent damaging the surface of the drum when the brush is accidentally tipped while spreading the ink on the drum.

Variations may be resorted to within the scope of the invention, and portions of the improvements may be used without others,

Having thus described my invention, I claim:

1. In a stenciling machine, the combination of an ink-fountain fast at the end of a supporting duct-shaft, said ink-fountain having means for measuring and expelling 3. In a stenciling machine, the combination of an ink-fountain fast at the end of a supporting duct-shaft, said ink-fountain having means for measuring and expelling a predetermined charge of ink from said fountain, and means to fasten the duct-shaft to a supporting bracket, said duct-shaft being bodily removable with the fountain upon releasing the fastening means.

4. In a stenciling machine, the combination of an ink-fountain fast at the end of a supporting duct-shaft, said ink-fountain having means for measuring and expelling a predetermined charge of ink from said fountain, and means to fasten the ductshaft to a supporting bracket, said duct-shaft extending through the supporting bracket and having a hole therein through which the ink is forced out upon the inner wall of a drum revolubly mounted upon said shaft, and means to prevent the leakage of ink through the hole, while the ink is not being ejected by the expelling means in the fountain.

5. In a stenciling machine, the combination of an ink-fountain fast at the end of a supporting duct-shaft, said ink-fountain having means for measuring and expelling a predetermined charge of ink from said fountain, and means to fasten the duct-shaft to a supporting bracket, said ductshaft extending through the supporting bracket and having a hole therein through which the ink is forced out upon the inner wall of a drum revolubly mounted upon said shaft, and means to prevent the leakage of ink through the hole, while the ink is not being ejected by the expelling means in the fountain, said last-mentioned means including a self-closing check-valve held in a closed position by a backing spring yieldable to the ink when under the pressure of the expelling means.

.6. The combination with a stenc-iling machine including a revolubly-mounted drum, of an ink-fountain fast at the end of a hollow shaft upon which the drum is mounted, and an ink-brush having a handle, and a hole in the body of the handle designed to engage an extension of said hollow shaft which affords a support for said brush.

7. The combination with a stenciling machine including a revolubly-mounted drum, of an ink-fountain fast at the end of a hollow shaft upon which the drum is mounted, and an ink-brush having a handle, and a hole in the body of the handle designed to engage an extension of said hollow shaft which affords a support for said brush, said brush being bodily removable for oporation, and said hollow shaft serving as a support for the drum, a passage for the ink and a support for the brush.

8. In a stenciling machine, the combination with a revoluble drum, of a fixed shaft on which the drum rotates, said shaft having an opening therein and supporting at the end thereof an ink-reservoir having comninnication with the opening, and an inkbrush normally supportable (on the fixed shaft, over said opening and removable to expose said opening, said brush including a grasping handle and a body into which the bristle-head of the brush is slidably mounted.

9. An ink-brush comprising a brushholder and a handle therefor, said brushholder having a socket whereby the brush may be supported upon a stud, and means whereby a bristle-carrying member may be slidably mounted in said brush-holder.

10. An ink-brush comprising a brushholder and a handle therefor, said brushholder having a socket whereby the brush may be supported upon a stud, means whereby-a bristle-carrying member may be slidably mounted in said brush-holder, and means whereby the bristle-carrying member may be fastened to the holder for preventing accidental displacement therefrom.

11. An ink-brush comprising a brushholder and a handle therefor, said brushholder having a socket whereby the brush may be supported upon a stud, means whereby a bristle-carrying member may be slidably mounted in said brush-holder, and means whereby the bristle-carrying member may be fastened to the holder for preventing accidental displacement therefrom, said last-mentioned means including a screw threaded into the brush-holder, and means to frictionally hold the bristle-carrying member in the brush holder.

12. An ink-brush comprising a brushholder and a handle therefor, said brushholder having a socket whereby the brush may be supported upon a stud and means whereby a bristle-carrying member may be slidably mounted in said brush holder, said means including grooves in the brush-holder designed to receive ribs forming an integral part of the bristle-carrying member, said ribs fitting snugly into the grooves in the brush-holder.

18. An ink-brush comprising a handle, a body having a socket whereby the brush may be supported upon a stud, and a bristlehead reversibly attachable to said body heneath said socket.

14. An ink-brush having a handle and a body disposed to receive and to hold a bristle-Head, and guards for the ends of the brush, for limiting the field of operation of said brush.

15. An ink-brush having a handle and a shell disposed to receive and to hold a bristle-head, and means for confining the movement of said brush, said means including plates fast to the bristle-head, said plates overextending the bristle-head at the ends thereof to prevent the bristles from reaching the ends of an ink-receiving surface having a rim at the end thereof for engagement with the ends of the plates.

16. In combination, an ink-fountain, means within said ink-fountain for measuring and expelling a charge of ink from said fountain, said means including a cylinder having an inlet port communicating with the fountain, a piston in said cylinder, a fingerpiece for operating said piston from the outside of said fountain, said cylinder having an outlet port, a duct shaft leading from the outlet port of the cylinder, and a stencil drum on said shaft.

17. In combination, an ink-fountain, means within said ink-fountain for measuring and expelling a charge of ink from said fountain, said means including a cylinder having an inlet port communicating with the fountain, a piston in said cylinder, a finger-piece for operating said piston from the outside of said fountain, said cylinder having an outlet port, a duct shaft leading from the outlet port of the cylinder, a stencil drum on said shaft, and means for automatically closing the duct in said duct shaft against leakage.

LINDEN A. THATOHER. 

